Mop wringer



FIG. 1 is a top right front perspective view of a mop wringer showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof; the left side elevational view being a mirror image;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a mop wringer, as shown and described. 